code: def CAT(*categories, **kwargs):
      """Experimental `Categorical` syntax, wherein all parameters other than `categories` are
      keyword-only arguments and all non-keyword arguments comprise `categories` itself. Furthermore,
      Python's Ellipsis (`...`) may be provided as the last non-keyword argument as an alternative to
      the more verbose `optional=True`
  
      Parameters
      ----------
      *categories: Tuple
          Values of the returned `Categorical`'s `categories`. If the last element of `categories` is
          `...`, it will be removed and the value of "optional" in `kwargs` will be overridden to True
      **kwargs: Dict
          Keyword arguments provided to initialize `Categorical`. In other words, all `Categorical`
          arguments other than `categories`. If the last element of `categories` is `...`, then the
          value of "optional" in `kwargs` will be overridden to True, whether or not "optional" was
          already given in `kwargs`
  
      Returns
      -------
      Categorical
          Instantiated with `categories` and `kwargs`
  
      Examples
      --------
      >>> c0 = Categorical(["a", "b", "c"], optional=True)
      >>> c1 = CAT("a", "b", "c", ...)
      >>> assert c0 == c1
      >>> c2 = Categorical([5, 10, 15], transform="identity")
      >>> c3 = CAT(5, 10, 15, transform="identity")
      >>> assert c2 == c3
      """
      if categories[-1] is ...:
          categories = categories[:-1]
          kwargs["optional"] = True
  
      return Categorical(list(categories), **kwargs)
  
file_path: hyperparameter_hunter/tests/test_i_o/test_result_reader.py
imports: from hyperparameter_hunter import FeatureEngineer, Categorical
  from hyperparameter_hunter.i_o.exceptions import IncompatibleCandidateError
  from hyperparameter_hunter.i_o.result_reader import validate_fe_steps
  from hyperparameter_hunter.space.dimensions import RejectedOptional
  import pytest
label_desc: Use image node_id 1 for calling a global function with example usage: CAT() and returns: Categorical